Numerous sophisticated locking systems utilize both mechanical locks and electrical or electronically operated locks. As an example, a building entrance may have an electronic controlled lock mechanism while the individual doors in the building have mechanical locks. Persons with authorized access to an individual door would have a hybrid key having one portion to operate the electronic lock and another portion to operate the particular mechanical door lock. For example, the electronic portion would provide access to the perimeter doors of a building while the mechanical lock would provide access only to the individual's office. This is only one of a number of possibilities and circumstances where hybrid locks and keys are or could be used.
The concept of a single key for operating both mechanical and electrical locks has been known for approximately 20 years, see U.S. Pat. No. 3,660,624 granted May 2, 1972. More recent patents showing electronic keys and locks therefor include U.S. Pat. Nos. 4,438,426 granted Mar. 20, 1984; 4,697,171 granted Sept. 29, 1987; and 4,712,398 granted Dec. 15, 1987.
The keys for operating electrical/electronic locks are commonly quite expensive due to the circuitry that is required to be carried in the key. If the key is only an electronic key without any mechanical operation and a person loses his key, the electronics of the system could be changed without great expense to prevent compromise of the lock and a loss of security. Also, if there is a hybrid key including both electronic and mechanical portions, and a person loses the key, the mechanical lock could be changed by changing the mechanical lock cylinder, and if the electronic and mechanical portions of the key are integral, this involves discarding, i.e., throwing away, the very expensive electronic portion of the key.
There appears to be a need in the art for a hybrid mechanical/electronic key in which the expensive electronic component can be easily separable from but usually rigidly secured to the mechanical components so that if keys need to be replaced, the mechanical component only can be replaced while the electrical or electronic component of the key can be maintained by removing from one key frame and placing on another.